Mech17

I realize it is probably a long shot for this particular forum, but would anyone who might have happened to have installed a megasquirt on a renix system know how to best get a tach signal into the megasquirt? I can't use the coil because I will be controlling ignition. Would the best way just be to buy and install a trigger wheel and sensor on the harmonic balancer?

DIYjoe

Suscribing; I am also looking at doing this.... F this renix junk lol

N20jeep

try tapping into a fuel injector harness.

radio flyer

The negative wire on the coil. I believe wire is black with a blue tracer

Bustedback

A trigger wheel would be the easiest for the MS set up.

Mech17

Wow I forgot to check this thread. I started a more specific one instead.
I can't use the coil because the ultimate goal is to control ignition. I think I may try notching an extra balancer I have for a trigger wheel. If it'll work, I'll start my true thread next week sometime. If not, it'll be awhile while I wait for a trigger wheel to get here.

Mech17

^^control ignition AFTER getting the hang of fuel^^

Darkman

I have heard this so many times over the years, I want to shoot whoever started it!

If your going to choose one over the other, I would do ignition BEFORE fueling. Much more advantageous. Until you get into boosted applications, 80% or more of your power increase will come from controlling spark maps.

Sure, most of your drivability improvements will come from fueling. Easier starts (if dialed in right).

Fueling will require tinkering over time to get everything perfectly dialed in. While spark maps can be tuned once, and for the most part never touched again.

Fuel only control by cheating and grabbing the tach signal off the coil, is easy from a wiring perspective. From my own experiences, I would never waste my time to do fuel only control. I would start by getting a proper and usable rpm signal, and tart with ignition only (if a choce between one or the other has to be made).

Gee oh Dee

Really old thread, but Renix is the better of the operating systems.

Mech17

Wow this thread started back up just in time. I "understand" the advantages of spark just as well as fuel. And if you look at my other thread (which is just as old and outdated as this one) you'll know that I don't even plan on doing this for all that much boosted performance. Its Just to learn how to do this kind of stuff with a side goal of more mpgs and a little power.

I already have gotten a trigger wheel and tested it on a metal lathe with a CPS sensor from my parts jeep. Hopefully in the next week or so I'll start the actual install and start posting pics on my other thread.

Lead Foot

May be a stupid question. But why cant you just use the existing signal coming from the existing CPS? Im very interested in this as I am planning on megasquirting my stroker. Have you found any helpful threads?

Mech17

The 4.0 uses a 66-2-2-2 wheel which isn't supported by the megasquirt software. And I haven't looked in awhile, but I didn't find much with people megasquirting jeeps.

Lead Foot

ah makes sense. When I first built my stroker I made the MAP sensor adjuster to "trick" the ECU. My OCD kicked in after I read through the complete fuel injection manual on these 4.0 engines and found that the ECU doesnt always take the MAP sensor into consideration. SO naturally I wanted to install and program a setup that would let me tune every detail. Just havent found much info on wiring it into a Jeep. Ill be sure to follow your thread.

Mech17

That's cool. Hopefully it becomes a useful one. And don't be afraid to yell at me to keep stuff coming because I'm pretty bad about staying up with these things. Did you find my other thread? I haven't looked at it in awhile. Haha

Mech17

Oh nevermind I guess I never made it. Haha